The present invention relates to thermostatic apparatus. More particularly, it relates to a means and method for calibrating a thermostatic assembly.
In thermostatic apparatus for controlling the temperature in a residential or office type accommodations, especially those having a resistance type thermal sensor, an electrical potentiometer is incorporated into the circuit to allow a range of adjustments of temperature at which the thermostat is to control the ambient. In such circuits heretofore, it has been found necessary to include one or more trim potentiometers in order to allow a proper calibration of the thermostat to accomplish the required degree of accuracy of the selective adjustments. In such arrangements, the temperature selecting knob or set point pointer is keyed to the shaft of the temperature selecting potentiometer in a predetermined position relative to the shaft which approximates the desired control point relative to a preestablished dial. Since it is only an approximation of the desired control point, the auxiliary adjustable trim resistors are necessary to gain the required degree of accuracy. Such an arrangement is relatively costly both from the point of view of additional parts, the additional labor for the installation of those parts and the complexity of accomplishing the calibration.